I would like to learn a couple of languages (polish and Japanese - I already learned Spanish to a decent degree) but it seems like every solution is closed source.
I would use books but listening (and speaking) are very important and books won’t help with those.
What would you guys recommend?
Duolingo is useful for wasting time while feeling like you are learning however it isn’t a great tool for learning if that is your goal.
I hear this opinion a lot, and I’d just like to add it manages to help with some exposure and repetition at the very least. I’m sure you’re more knowledgeable than myself with learning languages, but I’ve been using Duolingo to learn Japanese for a little while now and have managed to pick out basic hiragana and katakana here and piece together small words.
I don’t have any delusions that I’ll be fluent if I finish this course, but if it can help me learn the characters it’s worth the time to me.
A lot of people reduce Duolingo to their app, but they offer a big website on which you get a lot of explanations
so what is?
Comprehensive input:
www.dreamingspanish.com
Comprehensible input, lots of it. Classes, grammar books ,flash cards, and the like are useful supplements, but only a lot of time with the language works in the long run.